geological observation in deep submarine engineering is a crucial means for the development of marine science of the deep sea and plays an important role in revealing the dynamic response process of recent sediments under the action of deep marine power and in deeply understanding the geological process of marine power.
Compared with another main sediment transport process on the earth, namely the river turbidity current, the submarine turbidity current is still very little known. Due to the fact that the turbidity current is mostly generated in a deep-water area, the cost and risk of site observational study are high; long-term and continuous observation is required due to the unpredictability of the generation of the turbidity current; and observation apparatus are either broken or lost due to the destruction from the turbidity current. Low-velocity and low-concentration small turbidity currents in lakes and submarine canyons can be conveniently observed in situ. However, there are only three cases available for the understanding of large turbidity currents: the Var canyon, the Zaire sediment fan, and the canyon/manila trench in the southwest of Taiwan, China. These scanty data are obtained mainly through analysis on the fracture sequence of communication cables and drilling samples.
Due to the unpredictability of the forming mechanism of the turbidity current, observation and research of the submarine turbidity current are much more difficult than those of the lakebed turbidity current. Site observation of the submarine turbidity current mainly aims at low-velocity turbidity currents and is carried out in submarine canyons in most cases, and the submarine turbidity current is monitored mainly by means of a turbidimeter, an ADCP, and equipment which can only fulfill short-term monitoring on a certain parameter of the turbidity current, but cannot fulfill long-term submarine monitoring. So far, there is no apparatus that can withstand the impact from the turbidity current without being damaged.
The turbidity current is the key to solving many basic science problems of marine geology and sedimentology, and is closely linked with the study of the application of marine resources and energy and to preventing submarine hazards. Due to the unpredictability and destruction of the turbidity current, how to realize real-time and continuous on-site observation of the turbidity current is still a bottleneck restraining the research of the turbidity current.